Camera shutter



June 7, 1938. H. R. DARLING 2,119,845

CAMERA SHUTTER Filed Dec. 29, 1936 ZI ...[UIMMw HARRY RDARLING 1 N VENTOR.

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Patented June 7, 1938 UNITED STATES PATENT OFFICE CAMERA Sm ApplicationDecember 29, 1938, Serial No. 118,066

3 Claims.

This invention relates to photography, and more particularly to shuttersfor inexpensive photographic cameras.

One object of my invention is to provide a shutter in whichcomparatively light pressure on the trigger is all that is necessary formaking an exposure. Another object of my invention is to provide ashutter in which the shutter operating spring is a very light-weightspring and is one which will make the shutter blade move without causingit to shake or jar. Another object of my invention is to provide ashutter cover plate on an extension of the trigger and to use a springfor holding this plate in one direction which is much heavier than theshutter operating spring, in order to cause the shutter parts to movesmoothly. Still another object of my invention is to provide a flangeand arm connection between the cover plate and shutter plate whichpermits energy to be stored in the operating spring by moving the coverplate while .the shutter plate remains stationary. Another object o! myinvention is -to provide connections between the cover plate and shutterplate permitting the former to be moved the greater part of its maximummovement before allowing movement of the shutter plate, and otherobjects will appear from the following specication, the novel featuresbeing particularly pointed out in the claims at the end thereof.

Coming now to the drawing wherein like reference characters denote likeparts throughout:

Fig. 1 is a rear elevation of a camera shutter constructed in accordancewith and embodying a preferred form of my invention. Fig. 2 is a viewsimilar to Fig. 1, but with the parts moved to a different position.

Fig. 3 is a view similar to the preceding views, but with the parts instill another position.

Fig. 4 is a cross-section on line 4-4 of Fig. 1, and

Fig. 5 is a fragmentary detail, partially in section, showing theinterconnecting shutter and cover blade, rlange and arm.

This shutter is an improvement vover the shutter shown in U. S. Patent1,997,331, Fuerst, granted April 9, 1935.

Like the shutter shown in the above patent, this shutter is of thesimplest construction in which a shutter casing I can be suitably madeof molded material this shutter casing supporting, on a pivot 2, ashutter blade 3. The shutter blade 3 is preferably connected to a coverblade 4 by means of a spring 5, one end of which engages a lug 6 on thecover blade, and the other end of which engages a lug I on the shutterblade. Energy is stored in this spring by moving the cover blade 4 bymeans of a camera trigger l which is attached to a shaft 9 passingthrough the front wall 'I0 of the shutter cover and adapted to make anexposure.

The similarity between the shutter shown in the above-mentioned patentand this application stops here. The present invention resides in part,in providing a ilange and arm connection between the shutter blade andthe cover blade, so arranged that movement of the cover blade in eitherdirection can take place without movement of the shutter blade, thusstoring up energy in the spring 5 to operate the shutter blade at apredetermined speed.

To accomplish this, I may provide on the shutter blade 3 a pair ofarcuately disposed flanges II which project up a relatively shortdistance from the shutter blade 3, as best shown in Fig. 5. To engagethese flanges, I provide a pair of downwardly-formed arms I2 on thecover blade, these arms being rounded and being adapted to swing behindthe flanges.

Referring to Fig. 1, when the trigger 8 is moved in the direction shownby the arrow, an arm I2 rides along the inside of the ange II during therst part of the trigger movement. As the trigger is moved from itsinitial position of rest, shown in Fig. 1, to the position shown in Fig.2, the arm I2, by engaging the ange II holds the shutter blade 3 againstmovement while energy is stored in the spring 5. When the parts movejust beyond the position shown in Fig. 2 and the arm I2 slips oi the endof the arcuate flange II, the spring 5 causes the shutter blade to snapquickly to the position shown in Fig. 3. In making this movement, theslot I3 in the shutter blade 3 swings past the exposure opening I4,which may form the diaphragm for a lens I5 mounted in the shutter frontI0 by means of a 4 suitable ferrule I6. As the slot I3 swingsI past thisopening, an exposure of predetermined duration takes place, beca-use apredetermined amount of energy has been stored in the spring 5 by theilrst part of the movement of the cover blade 4.

A very similar movement takes place when the shutter 8 is released, theparts being actuated by a spring Il which may be anchored on a post I8carried by the camera casing I at one end and may be anchored on a lugI9 carried by the shutter cover blade 4 at the other end. As the triggeris released, this spring causes the cover plate to move towards theposition shown in Fig. 1. In so doing, the arm I2 engages and slidesonthe arcuate flange II as shown in Fig. 3, thus holding the shutter bladeagainst movement until the arm slips off the end of the flange, at whichtime a predetermined amount of energy has been stored in the spring 5which returns the shutter blade toits initial position of rest.

With shutters of this type, it is, of course, necessary, to make anexposure, to have all of the apertures in the shutter in alinement.Thus, in making an exposure, the aperture I3 in the shutter blade 3 mustlie over the aperture I4 in the shutter casing and at the same time anaperture 20 in the cover blade 4 must likewise lie in alinement with theother two apertures. It is, therefore, desirable to move the cover bladeto the proper position before releasing the shutter blade.

In this shutter the trigger is moved in the same direction each time tomake an exposure, and consequently, as the parts return to their normalposition of rest, the aperture 20 in the cover blade 4 must be moved outof alinement with the exposure aperture I4 to prevent an exposure frombeing made as the shutter blade returns to its initial position of rest.With the construction above described, this movement is assured becauseas will be indicated from Fig. 3, the aperture 2B is already out ofalinement with the exposure aperture Il before the shutter blade 3 hasstarted its return movement. Consequently, when the parts get justbeyond the position shown in Fig. 3 and the arm I2 slips off the flangeII, the return movement of the shutter blade will not permit light topass through the aperture I 4, thus ruining a'lllm.

' 2 in a symmetrical pattern and the flange engaging arms I2 beingequally spaced away from the shaft 9.

The path of movement of the arms I2 is such that when the trigger 8 ismoved in the direction of the arrow shown in Fig. 1 for making anexposure, an arm rides against a flange until it slips oif the end, atwhich time the shutter blade will move to the position shown in Fig. 3.When pressure on the trigger 8 is released, the arm I2, of course, movesthrough the same path. However, during this movement, as indicated inFig. 3, it passes on the opposite side of the flange I2 which wasengaged during movement in the reverse direction. As the shutter bladereturns to its initial position, the flange passes beneath that part ofthe shutter blade 2| which' lies substantially in a plane, as indicatedin Fig. 5, only the arm I2 being formed downwardly to engage the flangeII.

Thus, in a complete cycle of movement, one arm moves up engaging oneside of the flange, slipping oi the ilange at the end and then in itsidle return movement passes around the opposite side of the flange idlywhile the opposite arm is in engagement with the opposite flange. Thus,the movement of the shutter blade is entirely controlled by the arm andflange connection with the shutter blade and sufficient energy is storedup in the light spring 5 for driving the shutter blade at a fixed speedin both directions, and this relative movement incidentally requiresthat the aperture 20 in the cover blade be properly positioned both formaking an exposure and for making a. light safe joint while the partsmove to an initial position of rest from which an exposure can be made.

What I claim as my invention and desire to be secured by Letters Patentof the United States is:

1. In a photographic shutter, the combination with an apertured shuttercasing, of an vapertured shutter blade, a pivotal support therefor nearone edge of the shutter casing, oppositely disposed anges carried byedges of the shutter blade symmetrically arranged with respect to thepivot, an apertured cover blind, a pivotal support therefor near anopposite edge of the shutter casing from the shutter blade pivot, atrigger directly attached to the cover blind, a pair of symmetricallyarranged arms carried by the cover blind and bent downwardly to engagethe oppositely disposed flanges on the shutter blade, a hairpin springconnecting the shutter blade and the cover blind, a heavier springconnecting the shutter casing and cover blind, one of the symmetricallyarranged arms on the cover blind being positioned to ride idly againstone of the symmetrically arranged flanges of the shutter blade whilestoring up energy in the hairpin spring and being adapted to ride offthe end of said ange, causing the hairpin spring to actuate the shutterthrough movement of the trigger, the relative locations of the pivotalsupports and apertures for the shutter plate and cover blind being suchthat said shutter aperture is in registration with the cover blindaperture when the slip-off of the shutter blade and cover blind occurs,whereby the shutter blade aperture may swing past these registeringapertures to make an exposure.

2. In a photographic shutter, the combination with an apertured shuttercasing, of a flange surrounding said casing, two pairs of symmetricallyarranged stops carried by said flange, of a pair of pivots eachpositioned between a pair of stops and each positioned on opposite sidesof said shutter casing near said flange, an apertured shutter blademounted on one pivot and including parts adapted to engage each f onepair of stops, said blade having a width greater than half the distancebetween the stops, a cover blind pivoted on the other pivot and having awidth greater than half the distance between the other pair of stops, aspring connecting the shutter blade and cover blind, a trigger foroperating the latter, apertures in the shutter blade and cover blindeach spaced from the pivotal mounts therefor a distance to register withthe aperture in the shutter, means normally holding the cover blind in aposition of rest, whereby movement of the trigger may move the coverblind aperture into registration with the shutter aperture,interengaging arms and flanges on the shutter blade and cover blind forcontrolling movement of the former by the latter, whereby movement ofthe cover blind by the trigger through a relatively small angle may movethe cover blind between its stops and tension the spring to make anexposure.

3. In a photographic shutter, the combination with an apertured shuttercasing, of a flange surrounding said casing, two pivots mounted near theflange of said casing on opposite sides of said aperture, a shutterblade pivotally mounted on one of said pivotsand adapted to swing backand forth between two stops mounted symmetrically with Vrespect to saidpivot adjacent the edges of said shutter casing, a cover blind pivotedon the opposite pivot and having parts adapted to engage a pair of stopsarranged on each side of said pivot adjacent the edges of said coverblind, a spring connecting the shutter blade and cover blind, a secondspring, stronger than the first, adapted to hold the cover blind in aposition of rest against one of said stops, the width of said coverblind being greater than half the distance between said stops, a triggerfor actuating the cover blind. and slidable connections on the coverblind and shutter blade for controlling the movement of the latter bythe former, whereby movement of said trigger through a relatively smallangle may actuate the shutter blade causing it to move between its stopsto make an exposure.

HARRY R. DARLING.

